A projection type display device such as a projector displays an image on a screen by projecting light rays emitted from a light source on a screen. However, the light rays are scattered when they transmit a light diffusion layer of the screen that displays a video image. When the scattered light rays interfere on a side of a viewer such as audience, antiglare arises on the screen. Brightness non-uniformity occurring due to the interference of light rays is called scintillation. There is a problem that this scintillation impairs the image. The brightness non-uniformity indicates that brightness in a display surface is not uniform.
For solving this problem, the following method has been disclosed (for example, Patent Document 1). A screen has a first substrate and a second substrate. A light scattering part is sandwiched between these two substrates. The light scattering part has a dispersion liquid in which a light scattering material is dispersed in a dispersion medium. When oscillation is given to at least one of the substrates, the light scattering material migrates in the dispersion medium. The light rays entering the screen pass through a light diffusion plate or the light scattering part. By this scattering of light, a scattered wave is formed. As a result of migration of the light scattering material, scattering distribution of the scattered wave and the phase of the scattered wave temporally change. This temporal change in scattering distribution and the temporal change in phase reduce the scintillation.